Digital cameras have become increasingly commonplace and are now available to consumers in many forms, including as point-and-shoot compact cameras and more complex single lens reflex cameras. Digital cameras are also often integrated into a wide range of other consumer electronic devices, including smartphones, tablet computers, and laptop computers. One feature associated with digital cameras that has proven especially popular with consumers, and that film cameras cannot provide, is the ability to show a continually updated preview image on a display as the user is preparing to capture an image. Indeed, many digital cameras have no optical viewfinder at all, and instead rely entirely on the preview image display to allow the user to frame an intended photograph. This continually updated preview image can be understood as displaying a digital video stream that originates at a digital image sensor within the camera, and that comprises a sequence of individual video frames which are displayed at a suitable frame rate. In addition to helping a photographer compose his or her shot, the preview image display also provides an easy way to view previously captured images and experiment with various visual effects which can be applied to an image.
Digital cameras therefore provide convenience and the ability to produce high quality images without the hassle, limitations, and cost associated with conventional film processing. However, existing digital cameras are not immune to the various photographic inconveniences which photographers have grappled with for years. For example, when photographing static objects or people, such as a group of tourists posing in front of the Arc de Triomphe, kinetic objects such as automobiles and passersby may spoil the shot. The intended subject may be partially or completely obscured by a person walking through the image foreground. Or a passing car may create an unwanted distraction in the image background. An image editing software application can be used to manipulate captured images after image data has been retrieved from the camera. Adobe® Photoshop® (Adobe Systems Incorporated, San Jose, Calif.) is one example of an image editing software application that can be used to remove an unwanted object from an image, and to replace it with a visually plausible scene, thereby producing a modified image that seems reasonable to the human eye.
Unwanted objects are particularly likely to enter the scene being photographed in crowded areas, such as at tourist attractions, where there are many people milling about. It also often occurs near busy streets, thus presenting the photographer with the challenge of “timing” the shot accurately to avoid including unwanted traffic in the picture. And while these are just two examples of situations where this challenge arises, unwanted objects can spoil photographs nearly anywhere. In the past, photographers have dealt with this challenge by attempting to carefully control the scene being photographed, although this is often impossible in heavily trafficked areas or when spontaneous photographs are sought. With the advent of digital photography it has become possible, in some cases, to remove unwanted objects from a photograph using an image editing software application. However, post-processing can require a level of skill and familiarity with the software that many users lack. Post-processing also takes time and often must be performed using a device other than that used to capture an image in the first place. These limitations represent substantial challenges to photographers faced with unwanted objects encroaching on their subjects, and especially, to photographers operating in crowded areas.